http://hdl.handle.net/1957/4573 Search the Channel search http://ir.library.oregonstate.edu/dspace/simple-search http://hdl.handle.net/1957/9092 Title: Performance of wood frame wall with thin shell ECC shear panel <br/> <br/>Abstract: The overall goal of this study was to evaluate an alternative to traditional wood framed shear wall construction. This study introduced the innovative idea of using a water and seismic damage resistant, wood-concrete- composite (WCC) construction instead of an all-wood design. The WCC design consisted of a thin shell of engineered cementitious composite (ECC) cast in composite with a traditional wood frame. The WCC wall was evaluated with regards to structural performance during lateral loading, cost and damage sustained during lateral loading. The WCC test results were compared to a traditional wood frame wall with OSB sheathing. Data from the monotonic tests of the WCC walls show that the average maximum load was 47.5 kN (10700 lb), average elastic shear stiffness was 1.78 kN/mm (10200 lb/in) and the average energy absorbed was 4810 J (42600 lb-in). Overall, the test results indicate that the WCC is comparable with or superior to the OSB wall in regards to shear strength, shear stiffness, energy absorption and ductility. During lateral loading tests the WCC wall appeared to sustain less damage than the OSB wall. Panelized construction of the WCC system may increase overall project cost but could provide many additional benefits such as decreased construction time and greater durability. The WCC design appears to be a viable shear wall system that should be refined and fully tested for building code compliance. <br/> <br/>Description: Graduation date: 2009 http://hdl.handle.net/1957/8940 Title: Corporate social responsibility in the forest products industry : an issues management approach <br/> <br/>Abstract: Business is a social institution and society has always designated a role for business which has been undergoing changes with changing societal values and paradigms. Thus while business has always had some responsibilities, the modern connotation of the words corporate social responsibility commonly refers to business assuming responsibilities in economic, social and environmental realms. Relevance and acceptance of this view regarding the role of business in society has been increasing and is especially important for sectors such as the forest products industry. However corporate social responsibility in the forest products industry is an under- investigated area, more so, in the US context. To fill this gap, this research investigates corporate social responsibility in the US forest products industry. This is done by first developing a general theoretical foundation about the concept of corporate social responsibility, followed by investigating students' perceptions regarding the success of the US forest products industry in fulfilling its economic, social and environmental responsibilities. These students were drawn from four academic majors at Oregon State University and University of Montana and their perceptions were assessed on items covering economic, social and environmental responsibilities that were developed in Finland. The results suggest that students with different academic majors perceive the US forest products industry's success in fulfilling its economic, social and environmental responsibilities differently. Differences in perceptions were also found between male and female students. Limitations associated with this study led to conducting a broader study by first identifying social and environmental issues associated with the US forest products industry and then assessing the perceptions of general society with regards to industry's performance on these issues. Issues were identified by developing a two stage framework that consists of key-informants interviews and a Delphi group decision-making technique. Societal perceptions were assessed relative to industry perceptions for developing insights into business and society interaction. This was done by developing an issues evaluation framework consisting the legitimacy gap and expectational gaps components. Results suggest that significant legitimacy and expectational gaps exist between societal respondents and industry managers, indicating managerial attention to the social and environmental issues facing the US forest products industry. <br/> <br/>Description: Graduation date: 2009 http://hdl.handle.net/1957/8318 Title: Chemical modification of wood : dimensional stabilization of viscoelastic thermal compressed wood <br/> <br/>Abstract: The tendency of wood to shrink and swell with changing moisture content remains as one of the most significant challenges to using wood in its many applications. Viscoelastic Thermal Compression (VTC) has been shown to significantly increase the density, strength and stiffness of wood. However, dimensional stability is still a concern. Active and passive chemical modifications have been developed which impart dimensional stability by chemically altering the wood substrate or physically blocking the vital pathways of water through the wood microstructure. The efforts of this research have been to develop an approach which combines the VTC process with a chemical modification process resulting in a novel wood-based product that exhibits improved structural properties, as well as a high degree of dimensional stability. Low-grade, plantation-grown hybrid poplar (Populus spp.) was impregnated with low molecular weight phenol-formaldehyde resin, acetic anhydride or tung oil and then densified in the VTC process. Water soak and boil tests were performed to investigate the influence of each treatment on thickness swell, antiswelling efficiency (ASE), irreversible swelling, and thickness recovery. Modulus of elasticity (MOE) was also examined for each treatment. Fluorescence microscopy was applied to determine the physical location and distribution of the impregnating reagents to better understand their role in imparting dimensional stability. PF and acetylation treatments were shown to increase the stability of VTC treated samples. ASE values for both PF and acetylation treatments were high, with a maximum value of 86% for the PF treatment and 56% for the acetylation treatment. Two different low molecular weight PF resins were tested and it was found that the higher MW resin was retained within the cellular structure to a greater degree and imparted greater dimensional stability. MOE was positively correlated to density but negatively correlated to weight percent gain for PF treated samples. All chemically modified samples had lower increases in MOE than unmodified control specimens compressed to the same final thickness. A sub-sample of higher density PF treated specimens had significantly higher MOE values and similar stability values compared to lower density samples. Tung oil treated samples showed no ability to swell the wood cell wall and remained in the cell lumens. Although dimensional stability may have increased on a very short-term basis due to physical obstruction of moisture, long-term stability was not improved with tung oil treatments. <br/> <br/>Description: Graduation date: 2008 http://hdl.handle.net/1957/8226 Title: Improving the durability of second growth timbers of naturally durable species <br/> <br/>Abstract: While the heartwood of many wood species exhibits excellent resistance to fungal and insect attack, this resistance is sometimes diminished in second-growth material of the same species. The reasons for the reduced durability are unclear, but they may reflect a combination of both higher proportions of sapwood as well as reduced levels of heartwood extractives. Second growth timbers are often faster grown and this accelerated growth may affect the production of toxic extractives present in the heartwood. Reduced durability may affect the reputation, quality, and values of the final products. One approach for maintaining the quality of naturally durable second-growth timbers is to supplementarily treat the wood with low concentrations of preservatives. In this research, we evaluated the ability of two commercially-available and environmental-friendly preservatives to protect both the sapwood and heartwood of teak, western red cedar, and coastal redwood. Cubes of these timbers and southern pine, a decay susceptible control, were vacuum-pressure treated with varying retentions of didecyldimethylammonium chloride (DDAC), and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOI), or alkaline copper quaternary (ACQ). Preservatives performance was assessed first in a leaching test. Preservative concentrations in the wood changed little after leaching. Durability improvement was assessed by exposing treated cubes to two decay fungi (Trametes versicolor and Postia placenta) in a soil block test. The results suggested that DCOI (0.6 kg/m3) and DDAC (4 kg/m3) improved sapwood durability of teak, redwood, and western red cedar. While the performance of all treated heartwood was better than the performance of the untreated samples, these differences were too small to delineate differences. These results provided weak evidence that supplemental treatment may enhance heartwood durability. Finally, we evaluated possible interactions between heartwood extractives and DDAC and DCOI, using a bioassay with Trametes versicolor and Postia placenta on agar medium. Sawdust of teak, coastal redwood and western red cedar were extracted with solvents of various polarities and impregnated on filter paper disks. The disks were placed on Petri dish surfaces previously inoculated with fungal suspensions. Western red cedar and teak extractives inhibited growth of the fungi, while coastal redwood extractives had no antifungal activity. Combinations of these extractives and chemical preservatives were no more efficient than the individual chemical. The results suggest that supplemental treatments do not synergistically interact with the heartwood extractives. <br/> <br/>Description: Graduation date: 2008